Under-pressure Chelsea boss Maurizio Sarri admits Sunday’s Carabao Cup final with Manchester City will result in “disaster” should they repeat the first 30 minutes of their Europa League clash with Malmo.

Sarri’s side produced an uninspiring display during a goalless first half against the Swedish side before eventually winning 3-0 to progress to the last 16 of the competition 5-1 on aggregate.

The Italian has come under increased scrutiny at Stamford Bridge after the club dropped to sixth in the Premier League, with Blues fans joining in with chants for him to be sacked during Monday’s FA Cup loss to Manchester United.

Chelsea’s recent dismal run included a 6-0 thrashing at City a fortnight ago and they will again face Pep Guardiola’s side this weekend with the first silverware of the season up for grabs.

Asked what will happen if his players reproduce the opening half an hour of Thursday’s performance, Sarri replied: “A disaster, of course.

“I think that we played the first 30 minutes without confidence. Nervous. It wasn’t easy for us to play this match, so I can understand my players for the first 30 minutes.

“We are in a difficult moment. We had problems with the fans in the last match at home, so it’s normal for the team to enter on to the pitch without confidence.

“Of course, to play our football we need confidence if we want to be in control of the match, to have ball possession, to move the ball very fast with one or two touches, we need confidence.”

Ross Barkley curled in Chelsea’s second goal (Adam Davy/PA)

After the half-time whistle was greeted with boos, Olivier Giroud’s 55th-minute tap-in eased the nerves, before Ross Barkley’s free-kick and a low strike from Callum Hudson-Odoi wrapped things up.

There were also some jeers when Sarri introduced midfielder Jorginho as a second-half substitute.

The Italy international, signed in the summer from Sarri’s former club Napoli, is regarded by many as embodying his manager’s ‘Sarri-ball’ philosophy, tactics which have recently come in for heavy criticism.

Sarri urged supporters to back the player and felt the team’s poor start to the game demonstrated his importance.

Rasmus Bengtsson was sent off for Malmo (Adam Davy/PA)

“I think in the first 30 minutes we understood why Jorginho is very important for our team. We were in trouble to exit from our half, on pressing,” he said.

“With Jorginho, it’s easier I think. I hope that our fans will be able to understand that Jorginho, for us, is really a very important player.”

Hudson-Odoi, who handed in a January transfer request amid interest from Bayern Munich, seized a rare start with his goal.

Sarri expects the 18-year-old to grow into the first team and said he would need to sell another winger in order to accommodate him now.

“You need to understand that, in the same position, we have Pedro, Willian and Hazard,” he said. “So it’s not easy for a young player to play with the consistency with his team-mates.

“I want to remind you that Callum, with this one, played 14 matches.

“There isn’t in England another 18-year-old player with 14 matches in the first team. So I think that we are using him in the right way at the moment. Of course, the 20 matches this season will be 30 matches in the next, and 40 in two years.

“If I am at the club and I want Callum on the club consistently, I have to sell another winger. Otherwise the manager is in trouble.”

The visitors were reduced to 10 men when Rasmus Bengtsson was sent off for a second yellow card before Barkley’s free-kick.

Malmo boss Uwe Rosler, who was proud of his players, feels Chelsea have plenty of work to do in order to gain revenge against his former club Manchester City at Wembley.

Asked about the Blues’ chances in the cup final, the German replied: “[Laughs] What do you want me to say? You want me to be honest?

“Manchester City are another calibre to us. But I’m so, so happy about my players and what they delivered today. City will ask more questions of Chelsea.”